(1) Field of the Invention
This invention relates to a device for the detection of at least one luminescent substance, with a radiation source for the emission of excitation radiation to the at least one luminescent substance, whereby the excitation radiation has at least one excitation wavelength at which the luminescent substance is excited to emit luminescent radiation, and with at least one radiation receiver which is insensitive to the excitation radiation for the detection of the luminescent radiation, whereby the luminescent substance is located in the interior of a measurement chamber which is essentially impermeable to the radiation to which the radiation receivers are sensitive, and whereby the radiation source is located outside the measurement chamber such that the excitation radiation is injected through a wall area of the measurement that faces the radiation source and is transparent for the excitation radiation though the measurement chamber into the interior of the measurement chamber.
(2) Description of the Prior Art
A similar device of the prior art is described in EP-A-0 640 828. It has a measurement chamber which has a wall area that is formed by a dichroitic mirror, behind which, outside the measurement chamber, a radiation source is located which emits an excitation radiation through the wall area at a wavelength of approximately 302 nm (UV) into the measurement chamber. In the interior of the measurement chamber, a plurality of reaction vessels are provided, in which samples are located that are marked with a luminescent substance. The luminescent substance is excited by the excitation radiation to emit a luminescence radiation, the wavelength of which is different from that of the excitation radiation. The measurement chamber is impermeable for the luminescent radiation. For the detection of the luminescent radiation, a CCD camera is located in the measurement chamber at some distance from the samples. This device of the prior art has a relatively complicated construction.
A device of the prior art described in U.S. Pat. No. 4,868,103 has a flashlamp as the radiation source and a photomultiplier tube as the radiation receiver. Between the radiation source and a sample that contains a luminescent substance to be tested on one hand, and between the sample and the radiation receiver on the other hand, there are respective optical interference filters. This device of the prior art is therefore correspondingly expensive.
U.S. Pat. No. 5,885,843 describes another device of the prior art with a measurement chamber in which a photoluminescence aerogel is located. As the radiation source, outside the measurement chamber a UV lamp is provided which emits UV radiation into the measurement chamber through an optical filter. The UV radiation excites the photoluminescent aerogel to emit visible luminescent light which is detected with a photodiode. To prevent the light emitted by the radiation source from reaching the photodiode, the optical filter is impermeable to the luminescent light. This device of the prior art also has a relatively complicated construction.
The object of the invention is therefore to create a device of the type described above which, with a simple and compact construction.